Liquid crystal display device, backlight used for same display device, method for driving same backlight and method for manufacturing same backlight

ABSTRACT

A Liquid Crystal Display (LCD), a backlight used for the LCD and a method for producing the LCD and the backlight are provided which are capable of inhibiting an increase in component counts and in assembling processes and of reducing them, thereby achieving low costs. A display image is obtained by arranging a backlight section being able to perform scanning as a single unit in a manner that it positionally matches a liquid crystal displaying section. The backlight section is provided with a plurality of scanning electrodes and light emitting layers each providing a different luminescent color, and being spatially separated from each other on a principal face of the backlight and scanning is performed on a plurality of light emitting layers providing a different luminescent color.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/381,737, filed on Mar. 16, 2009, and entitled “LIQUIDCRYSTAL DISPLAY DEVICE, BACKLIGHT USED FOR SAME DISPLAY DEVICE, METHODFOR DRIVING SAME BACKLIGHT AND METHOD FOR MANUFACTURING SAME BACKLIGHT,”which is a divisional of U.S. patent application Ser. No. 11/272,663,filed on Nov. 14, 2005, (issued as U.S. Pat. No. 7,598,939 on Oct. 10,2009), which is a divisional of U.S. patent application Ser. No.10/279,211, filed on Oct. 23, 2002 (now abandoned). The presentapplication also claims priority of Japanese Patent Application No.2001-324873 filed on Oct. 23, 2001. The entireties of these relatedapplications are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device, abacklight used for a same display device, a method for driving a samebacklight and a method for manufacturing a same backlight.

The present application claims priorities of Japanese Patent ApplicationNo. 2001-324873 filed on Oct. 23, 2001, which are hereby incorporated byreference.

2. Description of the Related Art

In recent years, a remarkable improvement in performance of a liquidcrystal display device (hereinafter being referred to an “LCD”) isyielded and also a remarkable progress in making its screen larger ismade.

The LCD having a large screen is used as a monitor for a personalcomputer or a like. Development work of a liquid crystal television byexpanding technology of the LCD with a large screen is activelyproceeding.

In such an application to the television, an improvement in performanceof displaying a moving picture in an LCD is strongly required. There aretwo main reasons for dissatisfactory performance of a conventional LCD.

The first reason is that a response speed in the LCD is low. The secondreason is that display using the LCD is performed by using illuminatinglight being applied constantly. Hereinafter, the second reason isdescribed in detail. In ordinary cases, in a CRT (Cathode Ray Tube)which performs display of moving pictures, a movie or a like, period ofnon-display is provided between displaying time or a screen and for asubsequent screen.

In the CRT, an image screen is produced by scanning using an electronbeam on a fluorescent material. As a result, fluorescent light for apixel disappears after being scanned and does not appear until asubsequent screen scanning period starts.

Moreover, in the case of a movie, due to a period required for feeding afilm existing between displaying time for a screen and a subsequentscreen, illuminating light is intercepted, in ordinary cases, duringthis period.

On the other hand, in the case of the LCD, since light fed from abacklight is applied constantly, a non-display period between displayingtime for a screen and for a subsequent screen does not exist. Therefore,even if a moving picture is displayed using the LCD, the moving pictureslook like as if they shake.

To solve this problem, a method is proposed in which light to be fedfrom the backlight is applied in synchronization with timing of scanningon the liquid crystal display screen. This method is disclosed ina-literature, for example, “First Response Liquid Crystal Display” (byTaira et al., AM-LCD 1998, p 113-p 116). In this case, the backlight ismade up of an LED (Light Emitting Diode) and is lit in synchronizationwith timing of scanning on the LCD. This causes a scanning screen like aCRT to be produced in a pseudo manner, thereby trying to improveperformance of displaying moving pictures.

For example, a backlight assembly to be used for an LCD having afluorescent layer disclosed in Patent Application Laid-open No. Hei9-258227 is provided with a plurality of cold cathode fluorescent tubeshaving a length being equivalent to a liquid crystal panel and beingstacked in layers in parallel and a pair of supporting plates adapted tosupport a fluorescent tube being coupled to an end of a cold cathodefluorescent tube, in which the fluorescent tube is sequentially lit toform a consecutive image on a screen and, in order to excite afluorescent material (phosphor) contained in a fluorescent layer, lighthaving a magenta color with a wavelength of 380 nm to 420 nm is emitted.

Moreover, Japanese Patent Application Laid-open No. Hei 10-10997discloses a method for driving a display device which places a pluralityof line-shaped light sources for emitting each of R, G, and B colors ona transparent light guiding plate made of an acrylic resin so that lighthaving each of the colors extends in a scanning line direction andhaving a backlight device with a width of the line-shaped light sourcesfor emitting each of the R, G, and B colors being equivalent to severaltens of horizontal pixel lines employed in the liquid crystal panel inwhich, when the horizontal pixel line of the display panel is selectedfor scanning, the line-shaped light source corresponding to the drivingline emits light having each of colors corresponding to its colorsignal.

These conventional backlight units adapted to apply light fed from thebacklight in synchronization with timing of scanning on the LCD presentproblems in that component counts increase and a rise in costs forfabrication are unavoidable. That is, when the LED is used, since manyLEDs have to be arranged on a surface of the backlight, the increase incomponent counts and in assembling processes are unavoidable. Thispresents a serious problem in the case of a large-screen-type LCD inparticular.

Moreover, even when a plurality of cold cathode fluorescent tubes isused, as a size of a screen increases, a number of the cold cathodefluorescent tubes increases. Therefore, a price of the backlight risesin the case of the large-screen-type LCD.

Thus, in the conventional scanning-type backlight, though performance ofdisplaying a moving picture is improved, costs for fabricating thebacklight are high and therefore it is impossible to make low a price ofthe LCD device.

SUMMARY OF THE INVENTION

In view of the above, it is an object of the present invention toprovide a liquid crystal display device, a backlight used for a samedisplay device, a method for driving a same backlight and a method formanufacturing a same backlight, each of which is capable of inhibitingan increase in component counts and assembling processes and of reducingthem, thereby obtaining the LCD and its backlight unit at low costs.

According to a first aspect of the present invention, there is provideda liquid crystal display device including:

a liquid crystal display section;

a backlight section used to feed illuminating light to the liquidcrystal display section,

wherein the backlight section includes a backlight face, a scanningelectrode portion of which is made up of a plurality of scanningelectrode groups each having a plurality of scanning electrodes, aplurality of light emitting layer groups, each of which is made up aplurality of light emitting layer each having a different luminescentcolor, and being spatially separated from each other on the backlightface; and

a scanning drive circuit to scan every the light emitting layer group,as a scanning unit.

According to a second aspect of the present invention, there is provideda liquid crystal display device including:

a liquid crystal display section;

a backlight section used to feed illuminating light to the liquidcrystal display section,

wherein the backlight section includes a backlight face, a plurality ofscanning electrodes, a plurality of light emitting layers each having adifferent luminescent color, and being spatially separated from eachother on the backlight face, and

a tone changing circuit to change light emitting time of each of theluminescent colors in a scanning direction in the backlight and thus tochange a color tone in a region being scanned.

According to a third aspect of the present invention, there is provideda liquid crystal display device including:

a liquid crystal display section;

a backlight section used to feed illuminating light to the liquidcrystal display section wherein a width of screen scanning in thebacklight section is larger than a width of screen scanning in theliquid crystal display section.

In the foregoing, a preferable mode is one wherein the width of screenscanning in the backlight section is an integral multiple of the widthof screen scanning in the liquid crystal display section.

Also, a preferable mode is one that wherein includes a unit to have ascanning phase in the backlight section lag behind a scanning phase inthe liquid crystal displaying section.

According to a fourth aspect of the present invention, there is provideda liquid crystal display device including: a liquid crystal displaysection;

a backlight section used to feed illuminating light to the liquidcrystal display section wherein the backlight section has a plurality ofscanning electrodes; and

a unit to have a scanning phase in the backlight section lag behind ascanning phase in the liquid crystal display section, wherein backlightlight is fed after a response by the liquid crystal display section.

In the foregoing, a preferable mode is one wherein, in the liquidcrystal display section, illuminating light for displaying is appliedfrom the backlight section to a pixel existing in a vicinity of aselected scanning line and illuminating light for displaying is notapplied from the backlight section to a pixel in a non-selected scanningline.

Also, a preferable mode is one wherein the liquid crystal displaysection is driven in a simple matrix manner.

Also, a preferable mode is one that wherein includes a unit to changelight emitting time in a region where light is being fed in a scanningdirection in the backlight, thus to change maximum luminance of light inthe region being scanned.

Furthermore, a preferable mode is one that wherein is provided with alight diffusing layer between the liquid crystal display section and thebacklight section to diffuse light fed from the backlight section in aplane direction inside the light diffusing layer.

According to a fifth aspect of the present invention, there is provideda liquid crystal display device including:

a liquid crystal display section;

a backlight section used to feed illuminating light to the liquidcrystal display device; and

a prism layer made up of a single layer or a plurality of layers used tochange light fed from the backlight section into light havingdirectivity, being mounted between the liquid crystal display sectionand the backlight section.

In the foregoing, a preferable mode is one that wherein the backlightsection, the prism layer, a light diffusing layer used to diffuse lightfed through the prism layer from the backlight section in a planedirection inside the light diffusing layer and the liquid crystaldisplay section, which are stacked in layers in this order.

According to a sixth aspect of the present invention, there is provideda liquid crystal display device including:

a liquid crystal display section;

a backlight section used to feed illuminating light to the liquidcrystal display section; and

an anti-EMI (Electro-Magnetic Interference) filter layer being mountedbetween the liquid crystal display section and the backlight section.

In the foregoing, a preferable mode is one wherein the anti-EMI filterlayer is mounted internally in the liquid crystal displaying section.

According to a seventh aspect of the present invention, there isprovided a liquid crystal display device including:

a liquid crystal display section;

a backlight section used to feed illuminating light to the liquidcrystal display section; and

wherein the backlight section, an anti-EMI filter layer, a lightdiffusing layer used to diffuse light fed through the anti-EMI filterlayer from the backlight section in a plane direction inside the lightdiffusing layer and the liquid crystal display section, and the liquidcrystal display section are arranged in this order.

According to an eighth aspect of the present invention, there isprovided a liquid crystal display device including:

a liquid crystal display section;

a backlight section used to feed illuminating light to the liquidcrystal display section; and

either of an infrared ray absorbing layer to absorb infrared rays or aninfrared ray reflecting filter layer to reflect infrared rays, bothbeing mounted between the liquid crystal display section and thebacklight section.

According to a ninth aspect of the present invention, there is provideda liquid crystal display device having four sides including:

a liquid crystal display section provided with a plurality of scanninglines and a plurality of signal lines;

a backlight section used to feed illuminating light to the liquidcrystal display section and being provided with a plurality of scanningelectrodes;

wherein a side at which there is placed a terminal portion of each ofthe plurality of scanning lines and the plurality of the signal lines inthe liquid crystal display section are different from a side at whichthere placed a terminal portion of the plurality of the scanningelectrodes in the backlight section.

In the foregoing, a preferable mode is one wherein light fed from thebacklight section is generated by discharge in a gas.

Also, a preferable mode is one wherein a gas is filled in the backlightsection in a hermetic manner and wherein light fed from the backlightsection is fluorescent light emitted from a fluorescent material(phosphor) excited by excitation light generated by discharge in thegas.

Also, a preferable mode is one wherein a fluorescent layer is mounted ona front face of the liquid crystal display section and wherein light fedfrom the backlight section, after having passed through the liquidcrystal display section, enters into the fluorescent layer.

Also, a preferable mode is one wherein the backlight section ismaintained under vacuum and has a scanning electrode used to scan anelectron source and an electron fed from the electron source is guidedinto a fluorescent layer and wherein light fed from the backlightsection is produced by accelerating electrons under the vacuum andinjecting the accelerated electrons into the fluorescent layer.

Also, a preferable mode is one wherein the backlight section is providedwith an electroluminescent device and light fed from the backlightsection is electroluminescent light.

Also, a preferable mode is one wherein the backlight section includes aplurality of light emitting layers each having a luminescent color, andbeing spatially separated from each other on a principal face of thebacklight, and in scanning of the backlight section, each of theluminescent colors is independently is scanned, and wherein timing ofscanning on a screen of the liquid crystal display section issynchronized with timing of scanning on a screen of the backlightsection.

Also, a preferable mode is one wherein the backlight section includes aplurality of light emitting layer groups, each of which is made up of aplurality of light emitting layers each having a different luminescentcolor, and being spatially separated from each other on a principal faceof the backlight, and in scanning of the backlight section, each of thelight emitting layer groups is scanned as a scanning unit, and whereintiming of scanning on a screen of the liquid crystal display section issynchronized with timing of scanning on a screen of the backlightsection.

Also, a preferable mode is one wherein screen scanning in the liquidcrystal display section and in the backlight section is performed in asame period.

Also, a preferable mode is one wherein a screen scanning period in theliquid crystal display section is equal to a screen scanning period inthe backlight section and wherein screen scanning in the liquid crystaldisplay section is performed once during a period when screen scanningin the backlight section is performed two or more times.

According to a tenth aspect of the present invention, there is provideda plane-type backlight including:

a first substrate and a second substrate being mounted apart from eachother wherein gas is fed into space existing between the first substrateand the second substrate and a portion surrounding the space is sealedin a hermetic manner;

a common electrode being mounted on the first substrate;

a plurality of scanning electrodes being mounted on the secondsubstrate; and

wherein a voltage is applied between the common electrode and each ofthe scanning electrode to cause discharging to occur in the spacebetween the first substrate and the second substrate and wherein lightis emitted by exciting a fluorescent material being arranged between thefirst substrate and the second substrate; and

wherein the common electrode is made up of electrodes formed so as to beat a same potential on an entire light emitting face.

According to an eleventh aspect of the present invention, there isprovided a plane-type backlight including;

a first substrate and a second substrate being mounted apart from eachother wherein gas is fed into space existing between the first substrateand the second substrate and a portion surrounding the space is sealedin a hermetic manner;

a common electrode being mounted on the first substrate;

a plurality of scanning electrodes being mounted on the secondsubstrate; and

wherein a voltage is applied between the common electrode and each ofthe scanning electrode to cause discharging to occur in the spaceexisting between the first substrate and the second substrate andwherein light is emitted by exciting a fluorescent material beingarranged between the first substrate and the second substrate andwherein the common electrodes and the plurality of scanning electrodesare made up of a plurality of belt-shaped electrodes being extended in asame direction; and

a unit used to sequentially select one scanning electrode out of theplurality of scanning electrodes.

In the foregoing, a preferable mode is one wherein the common electrodeand the plurality of the scanning electrode both being made up of thebelt-shaped electrodes are configured to deviate positionally from eachother by a half period.

According to a twelfth aspect of the present invention, there isprovided a plane-type backlight including:

a first substrate and a second substrate being mounted apart from eachother wherein gas is fed into space existing between the first substrateand the second substrate and a portion surrounding the space is sealedin a hermetic manner;

a common electrode being mounted on the first substrate;

a plurality of scanning electrodes being mounted on the secondsubstrate;

wherein a voltage is applied between the common electrode and each ofthe scanning electrode to cause discharging to occur in the spaceexisting between the first substrate and the second substrate andwherein light is emitted by exciting a fluorescent material beingarranged between the first substrate and the second substrate; and

a protrusion being protruded toward a side of discharging space existingbetween electrodes facing each other on at least one of the commonelectrode and the plurality of the scanning electrode.

In the foregoing, a preferable mode is one wherein the protrusion isplaced on a dielectric layer used to electrically insulate thedischarging space from the electrode.

Also, a preferable mode is one wherein the protrusion is placed on anelectrode being exposed in the discharging space.

Also, a preferable mode is one wherein the common electrode and theplurality of the scanning electrode are respectively made up of aplurality of belt-shaped electrodes being extended in a same directionand each of the belt-shaped electrodes corresponds to each luminescentcolor having one of RGB (red, green, and blue) colors.

Also, a preferable mode is one wherein the common electrode and thescanning electrode are made up of belt-shaped electrodes intersecting atright angles to each other and each of the belt-shaped electrodescorresponds to each luminescent color having one color out of the RGBcolors.

According to a thirteenth aspect of the present invention, there isprovided a plane-type backlight including:

a first substrate and a second substrate being mounted apart from eachother wherein gas is fed into space existing between the first substrateand the second substrate and a portion surrounding the space is sealedin a hermetic manner;

a common electrode and a plurality of scanning electrodes being mountedon the first substrate;

wherein a voltage is applied between the common electrode and thescanning electrode to cause discharging to occur in the space existingbetween the first substrate and the second substrate and wherein lightis emitted by exciting a fluorescent material being arranged between thefirst substrate and the second substrate and

a unit used to sequentially select one scanning electrodes out of theplurality of scanning electrodes.

In the foregoing, a preferable mode is one wherein, on the firstsubstrate, the common electrode and the plurality of the scanningelectrodes are formed in a same face and the belt-shaped scanningelectrode is arranged between common electrodes a plane of which is of acomb-teeth shape.

Also, a preferable mode is one wherein the common electrode and thescanning electrode are stacked in layers with an insulating filminterposed between the common electrode and the scanning electrode on aside of the first substrate and wherein an opening is provided on theelectrode mounted on a first layer out of the electrodes being stackedin two layers.

Also, a preferable mode is one wherein at least one of the commonelectrodes and of the scanning electrodes is made up of a plurality ofbelt-shaped electrodes and a control electrode used to inhibit expansionof light emission is mounted between two belt-shaped electrodes adjacentto each other.

According to a fourteenth aspect of the present invention, there isprovided a discharging-type backlight for a liquid crystal displaydevice including:

an auxiliary discharging region existing adjacent to an outside of alight emitting region for displaying in a light emitting region fordischarging in which scanning lines being adjacent to each other toinitiate light emitting for scanning do not emit light, which causesdischarging to occur immediately before initiation of at least lightemitting for scanning.

In the foregoing, a preferable mode is one wherein the auxiliarydischarging region keeps discharging continuously during light emissionfor scanning and discharging.

Also, a preferable mode is one wherein an area of an auxiliarydischarging electrode used to have discharging occur in the auxiliarydischarging region is smaller than that of an electrode used to emitlight for scanning and discharging.

Also, a preferable mode is one wherein a thickness of a dielectric layercovering the auxiliary discharging electrode is greater than that of adielectric layer covering an electrode used to emit light for scanningand discharging.

Also, a preferable mode is one wherein a fluorescent material is notplaced in a portion surrounding the auxiliary discharging region.

Also, a preferable mode is one wherein a partition wall is placedoutside of a light emitting region for discharging in which scanning isinitiated and invasion of light for discharging in a region in whichdischarging is kept continuously into a light emitting region forscanning is reduced.

Also, a preferable mode is one wherein a region in which light emissionfor scanning is initiated is placed outside of a displaying region.

Also, a preferable mode is one wherein an electrode for discharging toinitiate light emission for scanning is placed outside of the displayingregion.

According to a fifteenth aspect of the present invention, there isprovided a method for driving a plane discharging-type backlight whichincludes a first glass substrate and a second glass substrate, a firstelectrode formed on the first glass substrate, a second electrode formedon the second glass substrate, at least one of which is covered with adielectric layer, wherein gas is fed into space formed between the firstglass substrate and second glass substrate and a portion surrounding thespace is sealed in a hermetic manner and wherein a voltage is appliedbetween the first and the second electrode to have discharging occur ina space between the first and the second glass substrate and light isemitted by exciting a fluorescent material being placed between thefirst glass and the second glass substrate, the method including:

a step of constructing at least one of the first and second electrodesto have discharging occur of a plurality of belt-shaped electrodes; and

a step of applying a DC (direct current) voltage to one belt-shapedelectrode out of the plurality of belt-shaped electrodes during lightemission for scanning and discharging in a region in which thebelt-shaped electrode emits light for discharging and of applying a sinewaveform voltage or a rectangular waveform voltage to another electrodeopposed to the belt-shaped electrode.

In the foregoing, a preferable mode is one wherein scanning is performedon light emitting region for discharging by scanning a DC voltage to beapplied to the belt-shaped electrode.

Also, a preferable mode is one wherein intensity of light emitted forscanning and discharging is varied by changing a DC voltage value to beapplied to the belt-shaped electrode.

Also, a preferable mode is one wherein a width of a region of lightemission for scanning is varied by changing a number of belt-shapedelectrodes to which the DC voltage is applied.

Also, a preferable mode is one wherein luminance of light fed from thebacklight is varied by changing a frequency of an AC (alternatingcurrent) voltage to be applied to the another electrode.

According to a sixteenth aspect of the present invention, there isprovided a liquid crystal display device having a liquid crystal displaysection and a backlight described above and scanning on the backlightand scanning on the liquid crystal display section are performed in asame period.

According to a seventeenth aspect of the present invention, there isprovided a method for manufacturing a backlight including:

a step of forming a scanning electrode, a common electrode, and afluorescent layer on either of two substrates;

a step of forming a seal layer having a plurality of partitions oneither of the two substrates; and

a step of collectively forming a plurality of backlight units by bondingthe two substrates together and cutting the bonded two substrates forevery sealing partition and by filling gas in a hermetic manner intoeach sealing partition.

According to an eighteenth aspect of the present invention, there isprovided a method for manufacturing a backlight including:

a step of forming a scanning electrode, a common electrode, and afluorescent layer on either of two substrates;

a step of forming a seal layer having a plurality of partitions oneither of the two substrates; and

a step of collectively forming a plurality of backlight units by bondingthe two substrates together and filling gas in a hermetic manner andthen cutting the bonded two substrates filled with gas for every sealingpartition.

With the above configuration, a scanning electrode is formed internallyin a backlight section and scanning is performed on a surface of thebacklight section in a light emitting portion and, therefore, it ispossible to reduce component counts, to simplify manufacturingprocesses, and to reduce costs. Also, since illuminating light emittedfrom the backlight is scanned and non-displaying period is provided, aperformance of displaying moving pictures is improved.

With another configuration, since one time scanning is performed on ascreen in a liquid crystal display section within a predetermined periodand two or more times scanning are performed on a screen in a backlight,occurrence of a flicker can be prevented.

With still another configuration, since a protrusion is formed on a sideof discharging space existing between electrodes facing each other in abacklight, control can be exerted in a place in which discharge as seedsoccurs and in a place in which strong discharging occurs, thus enablinguniform and stable discharging to be achieved.

With still another configuration, since an auxiliary discharging area isformed in a place being adjacent to a region being scanned in abacklight and, in this auxiliary discharging area, discharging occursimmediately before occurrence of discharging in a head portion of theregion being scanned, or discharging is maintained all the time and,since excited atoms and molecules, electrons, or ions serving as seedsof discharge are fed, it is possible to have discharging that rises in astable and speedy manner occur, as in the case of other region beingscanned.

With still another configuration, since redundancy is provided to ascanning light emission region in a backlight, high reliability is givento a displaying characteristic of a liquid crystal display panel whichperforms driving for scanning by using the backlight.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages, and features of the presentinvention will be more apparent from the following description taken inconjunction with the accompanying drawings in which:

FIG. 1 is a diagram illustrating an LCD according to a first embodimentof the present invention;

FIG. 2 is a diagram illustrating an LCD according to a second embodimentof the present invention;

FIGS. 3A and 3B are timing charts each explaining operations of the LCDof the second embodiment;

FIG. 4 is a diagram illustrating configurations of an LCD according to afourth embodiment of the present invention;

FIGS. 5A and 5B are timing charts each explaining operations of the LCDof the fourth embodiment of the present invention;

FIG. 6 is a diagram illustrating configurations of an LCD according to aseventh embodiment of the present invention;

FIGS. 7A, 78, and 7C are timing charts explaining the LCD of a ninthembodiment of the present invention;

FIG. 8 is a diagram illustrating configurations of an LCD according to atwelfth embodiment of the present invention;

FIG. 9 is a diagram illustrating another configuration of the LCDaccording to the twelfth embodiment of the present invention;

FIG. 10 is a diagram illustrating still another configuration of the LCDaccording to the twelfth embodiment of the present invention;

FIG. 11 is a diagram illustrating configurations of an LCD according toan eighteenth embodiment of the present invention;

FIG. 12 is a diagram illustrating configurations of an LCD according toa twentieth embodiment of the present invention;

FIG. 13 is a diagram illustrating configurations of an LCD according toa twenty-first embodiment or the present invention;

FIG. 14 is a diagram illustrating configurations of an LCD according toa twenty-second embodiment of the present invention;

FIG. 15 is a diagram illustrating configurations of an LCD according toa twenty-fourth embodiment of the present invention;

FIG. 16 is a diagram illustrating configurations of an LCD according toa twenty-fifth embodiment of the present invention;

FIG. 17 is a diagram illustrating configurations of the LCD according tothe twenty-fifth embodiment which is a cross-sectional view of the LCDof FIG. 16 taken along a line A-A′.

FIG. 18 is a diagram illustrating configurations of the LCD according tothe twenty-fifth embodiment which is a dross-sectional view of the LCDof FIG. 16 taken along the line A-A′.

FIG. 19 is a diagram illustrating configurations of the LCD according tothe twenty-fifth embodiment which is a cross-sectional view of the LCDof FIG. 16 taken along the line A-A′.

FIG. 20 is a cross-sectional view illustrating configurations of the LCDof the twenty-sixth embodiment of the present invention;

FIG. 21 is a cross-sectional view illustrating configurations of the LCDof a twenty-seventh embodiment of the present invention;

FIG. 22 is a cross-sectional view illustrating configurations of the LCDof a twenty-eighth embodiment of the present invention;

FIG. 23 is a cross-sectional view illustrating configurations of the LCDof a twenty-ninth embodiment of the present invention;

FIG. 24 is an exploded view illustrating configurations of an LCD of athirtieth embodiment of the present invention;

FIG. 25 is an exploded view illustrating configurations of a backlightof the thirtieth embodiment of the present invention;

FIG. 26 is a cross-sectional view explaining configurations of abacklight of a thirty-first embodiment of the present invention;

FIG. 27 is a cross-sectional view explaining configurations of thebacklight of the thirty-first embodiment of the present invention;

FIG. 28 is a cross-sectional view explaining configurations of abacklight of thirty-second to thirty-fourth embodiments of the presentinvention;

FIG. 29 is a cross-sectional view explaining configurations of abacklight of a thirty-fifth embodiment of the present invention;

FIG. 30 is a cross-sectional view explaining configurations of abacklight of a thirty-sixth embodiment of the present invention;

FIG. 31 is a cross-sectional view explaining configurations of abacklight of thirty-seventh and thirty-eighth embodiments of the presentinvention;

FIG. 32 is a diagram explaining wires for electrodes employed in athirty-ninth embodiment of the present invention;

FIG. 33 is a diagram illustrating a waveform of a driving voltageemployed in a fortieth embodiment of the present invention;

FIG. 34 is a cross-sectional view showing a backlight of a forty-firstembodiment of the present invention:

FIG. 35 is a cross sectional view schematically illustrating basicconfigurations of a gas discharging-type backlight of the embodiment ofpresent invention; and

FIGS. 36A to 36F are cross-sectional views explaining manufacturingprocesses of a backlight of a forty-fifth embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Best modes of carrying out the present invention will be described infurther detail using various embodiments with reference to theaccompanying drawings.

First Embodiment

FIG. 1 is a diagram illustrating an LCD according to a first embodimentof the present invention. As shown in FIG. 1, the LCD of the presentinvention is provided with a liquid crystal display section 1 and abacklight section 2 adapted to supply illuminating light to the liquidcrystal display section 1, at a back of which a plurality of scanningelectrodes 3 is provided each performing scanning on a screen of boththe liquid crystal display section 1 and of the backlight section 2 at asame time. More particularly, the LCD is so configured that the,scanning electrode 3 is mounted at a back of the backlight section 2 andthat, by scanning on a surface of the backlight section 2 (see arrowsrepresenting a direction of “backlight scanning”), light is emitted in aregion for the scanning electrode 3 that has been selected. Byconfiguring above, reduction of component counts is achieved. Moreover,by providing a non-display period when scanning is performed onilluminating light emitted from the backlight section 2, a performanceof displaying moving pictures is improved.

In the LCD shown in FIG. 1, scanning directions on the backlight section2 and on the liquid crystal display section 1 are same. However, it isnot always necessary that scanning directions on the backlight section 2and on the liquid crystal display section 1 are same. That is, in theLCD of the present invention, for example, as shown in FIG. 2, thescanning direction on the backlight section 2 (see the arrow forscanning on the backlight section 2) and the scanning direction on theliquid crystal display section 1 (see the arrow for scanning on theliquid crystal display section 1) may intersect at right angles eachother. Even by configuring above, same effects as obtained in the firstembodiment can be achieved.

Second Embodiment

FIG. 2 is a diagram illustrating an LCD according to a second embodimentof the present invention. The LCD of the second embodiment of thepresent invention is made up of a liquid crystal display section 1 and abacklight section 2, in which the backlight section 2 has a plurality ofscanning electrodes 3 and a period of scanning on a screen of the liquidcrystal display section 1 and a period of scanning on a screen of thebacklight section 2 are same in which scanning on the screen of theliquid crystal display section 1 is performed once while scanning isperformed on the screen of the backlight section 2 “n” times.

The operation of the LCD of the second embodiment is explained presumingthat n=2, by using FIG. 3A-3B. In FIG. 3A-3B, the period of scanning onthe screen of the liquid crystal display section 1 and a period ofscanning on the backlight section 2 are same. Moreover, while scanningon the screen of the backlight section 2 is performed twice (see FIG.3B), scanning on the screen of the liquid crystal display section 7 isperformed once (see FIG. 3A). Therefore, same information is displayedon the screen of the liquid crystal display section 1 every two times'scanning on the screen of the backlight section 2.

Generally, the scanning on the screen of the liquid crystal displaysection 1 is performed at a frequency of as low as 60 Hz. When thescanning on the screen of the liquid crystal display section 1 and thescanning on the screen of the backlight section 2 are performed insynchronization at this frequency (60 Hz), light luminance distributionof a display signal at the frequency of 60 Hz occurs. This is perceivedby a person seeing the displayed screen partially to be a flicker. Byperforming the scanning on the liquid crystal display section 1 and onthe backlight section 2 at a speed being twofold higher compared withthe conventional case and in a manner that the scanning on both theliquid crystal display section 1 and the backlight section 2 issynchronous, it is possible to prevent the occurrence of a flicker.

Moreover, as in the case of the LCD of the present invention, byperforming scanning on the liquid crystal display section 1 and thebacklight section 2 during a period corresponding to a frequency of 120Hz and then by suspending the scanning on the screen of the liquidcrystal display section 1 to perform only the scanning on the screen ofthe backlight section 2, the occurrence of the flicker can be prevented.

Thus, an example of operations occurring when n=2, that is, when thescanning on the screen of the liquid crystal display section 1 isperformed once while the scanning on the screen of the backlight section2 is performed twice within a predetermined period of time is explained.

By performing the scanning on the screen of the liquid crystal displaysection 1 once and by performing the scanning on the screen of thebacklight section 2 multiple numbers of times within a predeterminedperiod of time, it is also possible to prevent the flicker.

Third Embodiment

An LCD of a third embodiment of the present invention has a scanningmechanism in a backlight section made up of a group of light emittinglayers each having a different luminescent color and a scanningelectrode portion in the backlight section is constructed of a pluralityof kinds of scanning electrode groups each having a plurality ofscanning electrodes.

Fourth Embodiment

FIG. 4 is a diagram illustrating configurations of an LCD according to afourth embodiment of the present invention. In the LCD of the fourthembodiment of the present invention, light emitting layers are spatiallyseparated from each other on a principal face of the backlight section 2and each luminescent color is scanned independently. The LCD of thefourth embodiment is explained by referring to FIG. 4.

The luminescent colors in the backlight section 2 are provided in a formof a horizontal stripe and one of three primary colors (red, green, andblue) occurs every third color stripe. One piece of the horizontalstripe for the luminescent color is handled as a scanning unit.

In the example shown in FIG. 4, a scanning unit in backlight section 4numbers 1, 4, and 7 represent the red color, the scanning unit inbacklight section 4 numbers 2, 5, and 8 represent the green color, andthe scanning unit in backlight section 4 numbers 3, 6, and 9 representthe blue color. In FIG. 4, simply for the sake of convenience in drawingpictures, each of the luminescent colors in red, green, and in blue isrepresented by patterns.

Scanning timing for operations of the LCD of the fourth embodiment isexplained by referring to FIGS. 5A and 5B. As shown in FIGS. 5A and 5B,after the scanning on the screen of the liquid crystal display section 1has been performed (see FIG. 5A), the backlight section 2 is scanned inorder of the scanning unit numbers 1 to 4, and to 7 to complete displayof the red color and then in order of the scanning unit numbers 2 to 5,and 8 to complete display of the green color and further in order of thescanning unit numbers 3 to 6, and to 9 to complete display of the bluecolor (see FIG. 5B). This achieves display of full colors.

Fifth Embodiment

In an LCD according to a fifth embodiment of the present invention, eachof luminescent colors is provided spatially in a separate manner withina face of the backlight and scanning is performed in unit of a pluralityof light emitting layers each providing light having a differentluminescent color. Its operations are described by referring to FIG. 4.In FIG. 4, scanning is performed on a set of the scanning units (1, 2,and 3) to have them emit light. Then, the scanning is performed on a setof the scanning units (4, 5, and 6) and then on a set of the scanningunits (7, 8, and 9) to have them emit light.

By operating as above, light is emitted in a horizontal stripe manner inwhich the red, green, and blue colors are arranged in an adjacentmanner, thus enabling scanning on a screen to be performed.

Moreover, after having the set of the scanning units (1, 2, and 3) emitlight, it is possible to have the sets of the scanning units (2, 3 and4) and (3, 4, and 5) emit light.

Furthermore, in this embodiment, the scanning can be performed on a setcontaining different luminescent colors as one scanning unit such as ascanning unit 4 shown in FIG. 6. In this case, scanning is performed inorder of the scanning numbers 1, 2, 3, 4, 5, 6, 7, 8, and 9 to have thememit light.

Sixth Embodiment

An LCD of a sixth embodiment of the present invention is described. Inthis embodiment, by changing light emitting time for each of luminescentcolors in a region in a scanning direction, a color tone in a region ina scanning direction is altered.

In the configuration shown in FIGS. 3A and 3B, light having a singlecolor is emitted for every one scanning unit. Therefore, highlighting ofa red display on a screen can be achieved by lengthening light emittingtime. Thus, by calibrating light emitting time for each luminescentcolor, it is possible to create a screen having a desired color tone.

Seventh Embodiment

FIG. 6 is a diagram illustrating configurations of the LCD according tothe seventh embodiment of the present invention. The LCD of thisembodiment is so configured that a width of screen scanning on a liquidcrystal display section 1 is smaller than that of screen scanning on abacklight section 2. In the configuration shown in FIG. 6, the width ofscreen scanning on the backlight section 2 is set to be larger than thewidth of screen scanning on the liquid crystal display section 1.According to the seventh embodiment, the backlight section 2 can befabricated at lower costs because fine working on the backlight section2 is not required.

Eighth Embodiment

In an LCD of an eighth embodiment, a width of screen scanning in abacklight section 2 is approximately an integral multiple of that ofscreen scanning in a liquid crystal display section 1. In the LCD of theabove seventh embodiment, a width of screen scanning in the backlightsection 2 is larger than that of screen scanning in the liquid crystaldisplay section 1. However, it is necessary that timing for scanning onthe liquid crystal display section 1 synchronizes timing for scanning onthe backlight section 2. In order to achieve this, the width of screenscanning in the backlight section 2 is set to be an integral multiple ofthe width of screen scanning in the liquid crystal display section 1.Thus, by multiplying one scanning signal, another scanning signal can beproduced and the scanning can be synchronized with each other.

Ninth Embodiment

FIG. 7 is a timing chart explaining operations of an LCD of a ninthembodiment of the present invention. In the LCD of the ninth embodiment,scanning on a screen of a backlight section 2 is performed in prior toscanning on a screen of a liquid crystal display section 1. When timingof scanning on the backlight section 2 is synchronized with timing ofscanning on the liquid crystal display section 1, scanning is performedat a same frequency and in a same phase state. In FIGS. 7A, 7B, and 7C,positions of scanning on a backlight section {circle around (1)} (seeFIG. 7B) and of scanning on the backlight section 2 (see FIG. 7A) are ina same phase and its phase lag is zero.

However, in general, response time required for lighting up thebacklight section 2 is shorter than that required for lighting up theliquid crystal display section 1. Therefore, if positions of scanning onthe backlight section and scanning on the liquid crystal display section1 match each other (see FIG. 7B), illumination by the backlight section2 is provided before a full response by the liquid crystal displaysection 1 is made.

In the LCD of the ninth embodiment, as shown as the position of scanningon the backlight section {circle around (2)}, a scanning phase in thebacklight section lags a scanning phase in the liquid crystal displaysection 1. By configuring as above, after a full response has been madein the liquid crystal display section 1, supply of backlight light ismade possible. This enables more clear images to be obtained. Thus, theLCD of the ninth embodiment can be applied not only when the scanningshown in FIG. 1 is performed, that is, when the direction of thescanning on the liquid crystal display section 1 matches that of thescanning on the backlight section 2 but also when the scanning shown inFIG. 2 is performed, that is, when the direction of the scanning on theliquid crystal display section 1 intersects that of the scanning on thebacklight section 2 at right angles.

Tenth Embodiment

In an LCD of a tenth embodiment, a liquid crystal display section 1 isdriven by a simple matrix form. In a simple matrix driven-type LCD, itis known that, as a number of scanning lines increases more, a contrastratio becomes lower. In the case of the simple matrix form, applicationof an excessive voltage to a pixel on a non-selected scanning line at atime of scanning on a screen causes low contrast.

However, in the liquid crystal display section 1 of the presentinvention, illuminating light for display is fed from a backlightsection 2 only to pixels existing in a vicinity of selected scanningline and no illuminating light for displaying is fed to an pixel on anon-selected scanning. Therefore, since display luminance of light fedfrom the pixel on the non-selected scanning line is lowered which causeslow contrast, a contrast ratio in the simple matrix driving-type LCD canbe improved.

The operation of an LCD having 1,000 pieces of scanning lines isdescribed as an example. When this LCD is driven by a simple matrix format a duty ratio of 1000, its contrast ratio becomes very low.

On the other hand, by using light having a width of a scanning line fedfrom the backlight being equivalent to ten pieces of the scanning linesin the liquid crystal display section 1 (by driving control on ascanning electrode existing at a back of the backlight section), acontrast ratio being obtained by driving the LCD by a simple matrix at aduty ratio of about ten can be realized. Thus, according to the presentinvention, even in the case of the simple matrix driving LCD, a highcontract ratio can be achieved.

Eleventh Embodiment

In an LCD of an eleventh embodiment, by changing light emitting time ina region in a scanning direction, maximum luminance of light in a regionbeing scanned is altered. Equal assignment of scanning line selectingtime in a backlight section to all scanning lines is not necessary. Forexample, by assigning longer time for selection of the scanning line ina center of a screen of the backlight section 2, luminance of light inthe center of the screen can be increased. By operating as above, lightluminance distribution on a whole screen can be set in a freely variablemanner.

Twelfth Embodiment

In an LCD of a twelfth embodiment, at least one of a light diffusinglayer 6 and at least one of a prism layer are provided between abacklight section 2 and a liquid crystal display section 1.

If a scanning electrode is mounted at a back of the backlight section 2,emitting of light in a region between the scanning electrodes is madedifficult. As a result, uniform illuminating light on an entire screenis made impossible.

In this embodiment, as shown in FIG. 8, the light diffusing layer 6 ismounted between the backlight section 2 and a liquid crystal displaysection 1 and light fed from the backlight section 2 is diffused in aplane direction inside the light diffusing layer 6. By configuringabove, uniform illumination is achieved in a position corresponding to aregion between scanning electrodes.

Moreover, when the liquid crystal display section 1 is superimposed onthe backlight section 2, a moire stripe is produced. This occurs becausea position and/or a pitch of a pixel of the liquid crystal displaysection 1 does not match a position and/or a pitch of the scanningelectrode existing at a back of the backlight section 2.

In order to solve these problems, the light diffusing layer 6 isincorporated which can effectively prevent the moire stripe.

Moreover, generally, light fed from the backlight section 2 is perfectlydiffused light in many cases.

In the LCD of the twelfth embodiment, as shown in FIG. 9, a single or aplurality of prism layers 7 is mounted to change perfectly diffusedlight into light having directivity.

In this case also, due to nonconformity in a pitch among the prismlayers 7, the scanning electrode existing at a back of the backlightsection 2, and pixels in the liquid crystal display section 1, the moirestripe occurs in some cases. To avoid this problem, combined use of theprism layer 7 and light diffusing layer 6 may be employed.

In the LCD of the twelfth embodiment in which both the prism layer andlight diffusing layer are employed, as shown in FIG. 10, the backlightsection 2, prism layer 7, light diffusing layer 6, and the liquidcrystal display section 1 are stacked in layer in this order.

Thirteenth Embodiment

As light to be fed from a backlight section 2, light generated bydischarge in a gas is used. In this case, discharging occurs between aplurality of scanning electrodes and a plurality of common electrodes.Moreover, by creating a plurality of partitions within the backlightsection 2 and feeding various kinds of gases into the partitions in ahermetic sealed manner, a plurality of luminescent colors can beobtained.

Fourteenth Embodiment

In an LCD of a fourteenth embodiment of the present invention, as lightto be fed from a backlight section 2, fluorescent light emitted from afluorescent material (phosphor) excited by light produced throughdischarge in a gas is used. In this case, discharging occurs between aplurality of scanning electrodes and a plurality of common electrodes.Single gas is fed into the backlight section 2 in a sealed manner.Moreover, by changing a color of a fluorescent material using a printingprocess, a different luminescent color can be obtained.

Fifteenth Embodiment

In an LCD of a fifteenth embodiment, as light to be fed from a backlightsection 2, light generated by discharge in a gas is used. The light,after having passed through a liquid crystal display section 1, enters afluorescent material. In this case, a fluorescent material layer isarranged on a front of the liquid crystal display section. A color ofthe fluorescent layer is changed by using a fluorescent material havinga different luminescent color in a plane direction. This enables displayof full colors.

Sixteenth Embodiment

In an LCD of a sixth embodiment, as light to be fed from a backlightsection 2, light produced by accelerating electrons in a vacuum and byhaving light generated by the acceleration of electrons enter afluorescent material is used. In the embodiment, an inside portion ofthe backlight section 2 is maintained under vacuum and scanningelectrodes each being able to scan an electron source are providedtherein. Moreover, arrangement is made so that an electron beam from theelectron source is guided into a fluorescent layer. By changing a colorof the fluorescent layer, the backlight section 2 having a plane faceportion adapted to emit light having a different luminescent color canbe achieved.

Seventeenth Embodiment

In an LCD of a seventeenth embodiment, as light to be fed from abacklight section 2, electroluminescent light is used. In theembodiment, an electroluminescent material made of an organic materialor inorganic material is used for backlight. By changing a color of alight emitting layer made of the electroluminescent material, lightproviding a different luminescent color can be obtained within a face.Moreover, by placing a scanning electrode group and a mechanism to driveit, a backlight section 2 being capable of performing scanning isobtained.

Eighteenth Embodiment

An LCD of an eighteenth embodiment has an anti-EMI (ElectromagneticInterference) filter between a liquid crystal display section 1 and abacklight section 2.

Ordinarily cases, electromagnetic interference occurs in a backlightsection irrespective of its type. As a result, noise or the like areproduced in the liquid crystal display device which causes a displayfailure. In the LCD of the above embodiments, since a scanning electrodeis placed for scanning, such the display failure presents a seriousproblem. In order to solve this problem, according to the eighteenthembodiment, as shown in FIG. 11, the anti-EMI filter layer 8 is placedbetween the backlight section 2 and the liquid crystal display device 1which prevents occurrence of the display failure.

Nineteenth Embodiment

An LCD of a nineteenth embodiment has an anti-EMI filter layer 8 withina liquid crystal display section 1. As the anti-EMI filter layer 8, amesh-shaped conductor is preferably used. The mesh-shaped conductor canbe easily fabricated in a thin film producing process performed in aliquid crystal display section 1.

When the anti-EMI filter layer is mounted outside of the liquid crystaldisplay section 1, a problem of a moire stripe caused by pitch driftsarises.

However, in the LCD of the present invention, since the anti-EMI filterlayer 8 is mounted within the liquid crystal display section 1, theanti-EMI filter layer 8 can be fabricated so as to have a position ofthe anti-EMI filter layer 8 be matched with the liquid crystal displaysection 1, which effectively serves for removing a moire stripe.

Twentieth Embodiment

In an LCD of a twentieth embodiment, as shown in FIG. 12, at least, abacklight section 2, an anti-EMI filter layer 8, a light diffusing layer6, and a liquid crystal display section 1 are provided in this order.

If the anti-EMI filter layer 8 is mounted outside of the liquid crystaldisplay section 1, a moire stripe is produced by a mesh-shaped conductorof the anti-EMI filter layer 8 and by a liquid crystal display section1. To avoid this, as shown in FIG. 12, the light diffusing layer 6between them is placed, which effectively prevents occurrence of themoire stripe.

Twenty-First Embodiment

In an LCD of a twenty-first embodiment of the present invention, asshown in FIG. 13, an infrared ray absorbing filter layer 9 or aninfrared ray reflecting filter layer 9 is placed between a liquidcrystal display section 1 and a backlight section 2.

Generally, an infrared ray is emitted, besides visible light, from abacklight section 2 at a same time. In some cases, this causesdeterioration of the liquid crystal display section 1 or overheatingphenomenon in the liquid crystal display section 1.

In the LCD of the embodiment, as shown in FIG. 13, the filter layer 9absorbing or reflecting an infrared ray 9 is placed between the liquidcrystal display section 1 and the backlight section 2. By configuring asabove, the occurrence of overheat in the liquid crystal display section1 is avoidable.

Twenty-Second Embodiment

In an LCD of the embodiment, a side at which there is placed a terminalportion of each of the plurality of scanning lines and the plurality ofthe signal lines in the liquid crystal display section are differentfrom a side at which there placed a terminal portion of the plurality ofthe scanning electrodes in the backlight section 2.

FIG. 14 is a diagram illustrating configurations of the LCD according tothe twenty-second embodiment of the present invention. By referring toFIG. 4, configurations of the LCD of the twenty-second embodiment aredescribed.

In the liquid crystal display 1, a scanning line and a signal line haveto be connected to an external circuit. Moreover, in the LCD of theembodiment, terminal portions taking out the scanning electrode line andcommon electrode line in the backlight section 2 is required. It isnecessary that, by performing positioning and positional adjustment ofboth the lines, they are superimposed on each other. As a result, whencompared with a conventional liquid crystal display device, morecomplicated taking-out of wires is required.

In the LCD of the embodiment, a scanning line of the liquid crystaldisplay section 1 is taken from one side out of four sides of the liquidcrystal display section 1 and a signal line is taken from other twosides out of the four sides and a scanning line of the backlight section2 is arranged on a side except these three sides. This enables compactmounting.

Twenty-Third Embodiment

In the twenty-third embodiment as a backlight, a plane-type backlight isused in which gas is fed into a space between a first substrate and asecond substrate and portions surrounding the space are sealed in ahermetic manner and wherein a common electrode is placed on the firstsubstrate and a plurality of scanning electrodes is placed on the secondsubstrate and a voltage is applied between electrodes to cause chargingto occur in the space between the substrates and light is emitted from afluorescent material placed between the substrates by excitation andwherein scanning mechanism to sequentially select the scanning electrodeis provided.

Twenty-Fourth Embodiment

In an LCD of a twenty-fourth embodiment, a backlight is an electrodeformed so that common electrodes are at same potential on an entirelight emitting face of a backlight. FIG. 15 is a diagram illustratingconfigurations of the LCD according to the twenty-fourth embodiment ofthe present invention. As shown in FIG. 15, in the embodiment, a commonelectrode 14 is placed so as to cover an entire surface of one substrate21. On another substrate. 22 is formed a plurality of scanningelectrodes 3 and on a side of the substrate 22 being opposite to thesubstrate 21 is provided a fluorescent light layer 5, which make up abacklight section 2. Moreover, in the example of FIG. 1, though thecommon electrode 14 is placed on an outside of a gas layer 12, thecommon electrode 14 may be fabricated on a side of the gas layer 12 ofthe substrate 21.

Twenty-Fifth Embodiment

In an LCD of a twenty-five embodiment, a backlight is made up of aplurality of belt-shaped common electrodes placed on one electrode and aplurality of belt-shaped scanning electrodes placed on another electrodewherein each of the common electrodes and each of the scanningelectrodes are arranged in a same direction. FIG. 16 is a diagramillustrating configurations of the LCD according to the twenty-fifthembodiment of the present invention. As shown in FIG. 16, the pluralityof common electrodes 14 on the substrate 21 is commonly connected to oneanother and are arranged in parallel. On a substrate 22 is arranged aplurality of scanning electrodes 3 in parallel.

FIG. 17 is a diagram illustrating configurations of the LCD according tothe twenty-fifth embodiment which is a cross-sectional view of the LCDof FIG. 16 taken along a line A-A′. The LCD of the twenty-fifthembodiment is provided with the substrate 21 having a plurality of thecommon electrodes 14 (belt-shaped electrode) arranged in parallel andthe substrate 22 having a plurality of scanning electrodes 3 and whereina fluorescent material layer 5 is placed on a face of the substrate 21being opposite to the substrate 22 and a gas layer 12 is provided so asto be sandwiched between the substrates 21 and 22.

In the embodiment, modified LCDs as shown in FIG. 18 and FIG. 19 may beemployed so long as it is so configured that the belt-shaped electrodecan be driven for scanning.

As shown in FIG. 18, the modified LCD is provided with the substrate 22having a plurality of scanning electrodes 3 and the substrate 21 havinga plurality of common electrodes 14 (belt-shaped electrode) placed inparallel to one another on a face of the substrate 21 being opposite tothe substrate 22 and wherein on a face of the substrate 21 beingopposite to the substrate 22 is formed the fluorescent material layer 5in a manner that it covers the common electrode 14 and a gas layer 12 isprovided in space between the substrates 21 and 22.

As shown in FIG. 19, another modified LCD is provided with the substrate22 having a plurality of scanning electrodes 3 and a fluorescentmaterial layer 5 formed in a manner that it covers scanning electrodes 3and the substrate 21 having common electrodes 14 (belt-shaped electrode)placed in parallel to one another on a face of the substrate 22 beingopposite to the substrate 21 and wherein on a surface of the substrate21 being opposite to the substrate 22 is formed the fluorescent materiallayer 5 in a manner that it covers the common substrate 14 and whereinthe gas layer 12 is provided in space between the substrates 21 and 22.

Twenty-Sixth Embodiment

In an LCD of a twenty-six embodiment, common electrodes 14 are made upof a plurality of belt-shaped electrodes placed in one direction andscanning electrodes 3 are also made up of a plurality of belt-shapedelectrodes placed in one direction and wherein both the commonelectrodes 14 and scanning electrodes 3 are deviated positionally fromeach other by a half period (a half pitch). In the LCD of thetwenty-fourth embodiment, discharging in space between the scanningelectrodes 3 does not occur easily.

However, in the LCD of the twenty-sixth embodiment, as shown in FIG. 20,the common electrodes 14 and the scanning electrodes 3 are deviatedpositionally from each other by a half period (half pitch) and whereinthe scanning electrodes 3 are formed in a position corresponding to aregion in which the common electrodes 14 are not formed. The LCD of thetwenty-sixth embodiment can be applied to the embodiments shown in FIG.17 and FIG. 19.

Twenty-Seventh Embodiment

An LCD of a twenty-seventh embodiment has a protrusion 15 protrudingtoward discharging space on a dielectric layer formed at least on oneside of a common electrode 14 or of a scanning electrode 3. FIG. 21 is across-sectional view illustrating configurations of the LCD of thetwenty-seventh embodiment of the present invention. As shown in FIG. 21,the protrusion 15 is provided on a surface of a plurality of scanningelectrodes 3 formed on a substrate 22.

By placing the protrusion 15 on a side of discharging space betweenelectrodes facing each other, control can be exerted on a place wheredischarge as seeds is produced and on a place where intense dischargingoccurs, uniform and stable discharging can be achieved.

Same effects as obtained in the above embodiment can be obtained notonly by mounting a discharging electrode on a dielectric layer beinginsulated from discharging space but also by mounting the protrusion 15on an electrode being exposed in the discharging space and by coveringthe protruded electrode with the dielectric layer and by partiallymaking smaller a thickness of the dielectric layer and by placing aprotrusion on a surface of a fluorescent material.

Twenty-Eighth Embodiment

In an LCD of a twenty-eighth embodiment, both a common electrode 14 anda scanning electrode 13 are made up of a plurality of belt-shapedelectrodes being placed in a same direction and each of the belt-shapedelectrodes serves as a backlight corresponding to light having one of R,G, B colors.

As shown in FIG. 22, by changing a color of a fluorescent material layer5, a color of fluorescent light can be changed in a position of thescanning electrode 3 selected for scanning. In this case, scanning oneach of the R, G, and B colors can be performed.

In the example shown in FIG. 22, the fluorescent material layer 5 isplaced on a side of the common electrode 14, however, it may be placedon a side of the scanning electrode 3. Moreover, it may be placed onboth the electrode substrates 3,14.

Twenty-Ninth Embodiment

In an LCD of a twenty-eighth embodiment, a common electrode 14 and ascanning electrode 3 are belt-shaped electrodes almost intersecting eachother at right angles and each of the belt-shaped electrodes serves as abacklight corresponding to luminescent color out of R, G, B colors.

As shown in FIG. 23, in an LCD) of the twenty-ninth embodiment, both thecommon electrode 14 and the scanning electrode 3 are made up ofbelt-shaped electrodes intersecting at right angles each other (a seriesof belt-shaped electrodes placed in a horizontal direction). In thiscase, scanning can be performed on each of the colors R, G, and B.

Thirtieth Embodiment

As a backlight employed in a thirtieth embodiment, a plane-typebacklight is used in which gas is fed into space between a firstsubstrate and a second substrate and a portion surrounding the spacefilled with the gas is sealed in a hermetic manner in which a commonelectrode 14 and a plurality of scanning electrodes 3 are mounted on thefirst substrate and discharging occurs in space between the substratesby a voltage applied between electrodes and a fluorescent materialarranged between the substrates is excited to emit light and in whichthe backlight has a scanning mechanism which sequentially selects ascanning electrode 3. FIGS. 24 and 25 are an exploded view illustratingconfigurations of the backlight of the embodiment.

In the example shown in FIG. 24, the common electrode 14 and thescanning electrode 3 are placed on a same substrate 22. The commonelectrode 14 is of a comb-teeth shape and between the common electrodes14 are arranged belt-shaped scanning electrodes 3.

Moreover, in the example shown in FIG. 25, the common electrode 14 andthe scanning electrode 3 are stacked in layers with an insulating film23 sandwiched between the common electrode 14 and the scanningelectrodes 3. To induce discharging, an opening 16 is formed on thescanning electrode 3 and the insulating film 23.

Thirty-First Embodiment

In the backlight employed in a thirty-first embodiment, at least one ofa common electrodes 14 and a scanning electrodes 13 are made up of aplurality of belt-shaped electrodes and among the belt-shaped electrodesis arranged an electrode which inhibits expansion of emitted light.FIGS. 26 and 27 are cross-sectional views explaining configurations ofthe backlight of the thirty-first embodiment of the present invention.Cutting plane lines A-A′ in FIGS. 26 and 27 correspond to an A-A′ lineshown in FIG. 16. In the example shown in FIG. 26, the common electrodes14 are placed on the substrate 21 and the scanning electrodes 3 on asubstrate 22. In the example shown in FIG. 27, the common electrodes 14and the scanning electrodes 3 are placed on a same substrate 22.

Discharging occurs between a pair made up of the common electrodes 14and the scanning electrodes 3. A control electrode. 17 is placed betweenthe scanning electrodes 14. In the example in FIG. 26, another controlelectrode 17 is placed between the scanning electrodes 3 and the commonelectrodes 14 on the substrate 22. This prevents discharging betweenneighboring electrodes, thus enabling localization of discharging space.

In the example shown in FIG. 27, the scanning electrodes 3 and thecommon electrodes 14 are arranged in a same manner on the substrate 22and the control electrode 17 is placed between a pair of the scanningelectrodes 3 and a pair of the common electrodes 14. This preventsdischarging between neighboring electrodes, thus enabling localizationof discharging space. A fluorescent material layer 5 is formed in amanner so as to cover the scanning electrodes 3 and the commonelectrodes 14.

The configuration using the control electrode 17 shown in FIG. 26 can beapplied to configurations of the electrode shown in FIGS. 15, 16, and24. Moreover, the configuration using the control electrode 17,irrespective of arrangement of the fluorescent material, can be appliedto configurations shown in FIGS. 1, 8, and 19.

Thirty-Second Embodiment

As a backlight employed in a thirty-second embodiment, as shown in FIG.28, a discharging-type backlight is used which is placed adjacent to anoutside of a display light emitting area in a discharging light emittingregion in which a neighboring scanning line to start emitting of lightfor scanning does not emit light and which has an auxiliary dischargingarea to have discharging occur immediately before a start of emittinglight for scanning. FIG. 28 shows a part of a cross-section indischarging light emitting region of the backlight having a first glasssubstrate 101 and a second glass substrate 201. On the first substrate101 are placed a common electrode 102 and a transparent dielectric layer103 and on the second substrate 201 are placed a scanning electrode 202,a white dielectric layer 203, and a fluorescent material layer 204.Moreover, in the auxiliary discharging area are provided an auxiliarydischarging electrode 104 and a light intercepting section 105. A sealmember 116 is also provided as shown in FIG. 22.

Thirty-Third Embodiment

A discharging-type backlight continues, all the time, discharging in anauxiliary discharging area during a period of emitting light forscanning and discharging.

In a head portion in which scanning is initiated, since time has elapsedafter a previous discharging and since no discharging occurs in anneighboring scanning line, if there is no discharging in a surroundingarea, discharging does not occur readily.

Next, as shown in FIG. 28, adjacent to a region being scanned of theabove head portion is formed an auxiliary discharging region in which,by having discharging occur immediately before occurrence of dischargingin the region being scanned of the head portion or by maintainingdischarging continuously and supplying excited atoms and molecules,electrons, and ions serving as seeds of discharge (that is, by using apriming effect), it is possible to start discharging that rises in astable and speedy manner, as in the case of discharging in other regionbeing scanned.

Thirty-Fourth Embodiment

A discharging-type of a thirty-fourth embodiment, as shown in FIG. 28,is so configured that an area of an auxiliary discharging electrode 104used to have discharging occur in an auxiliary discharging area issmaller than that of an scanning electrode 202 used to emit light forscanning and discharging or that a thickness of a dielectric materiallayer used to coat an auxiliary discharging electrode 104 is larger thanthat of a dielectric material layer used to coat an electrode to emitlight for scanning and discharging.

Thirty-Fifth Embodiment

In a discharging-type backlight to be used for a liquid crystal displaydevice, a fluorescent material is not placed in an area surrounding anauxiliary discharging region. It is preferable that intensity ofdischarging occurring in the auxiliary discharging area is as small aspossible. Therefore, by making an area of an electrode used to haveauxiliary discharging occur be narrower than that of a scanningelectrode or by making a thickness of a dielectric material layercovering an electrode be larger than that of a scanning section, theintensity of the auxiliary discharging can be properly controlledwithout reducing a priming effect.

As shown in FIG. 29, by configuring the backlight so that a fluorescentmaterial layer 204 is not placed in an auxiliary discharging region, itis possible to prevent light from a fluorescent material layer emittedby auxiliary discharging from turning around a region being scanned oraround a displaying region.

Thirty-Sixth Embodiment

In a discharging-type backlight to be used for a liquid crystal displaydevice, a partition wall 106 to reduce invasion of discharging lightinto a region of light emitting for discharging and scanning in a regionin which discharging is maintained continuously (see FIG. 30) is placedoutside of a discharging light emitting region in which discharging isstarted. FIG. 30 is a cross-sectional view explaining configurations ofthe backlight of the thirty-sixth embodiment. As shown in FIG. 30, byseparating an auxiliary discharging region from a region being scannedusing a shielding structure such as the partition wall 106 in a range inwhich a priming effect can be obtained, it is possible to reduce adetriment that a fluorescent material in the region being scannedexcited by ultraviolet rays produced by an auxiliary discharge, wherebyfluorescent light is emitted from the fluorescent material.

Thirty-Seventh and Thirty-Eighth Embodiments

In a discharging-type backlight employed in the thirty-seventh andthirty-eighth embodiments, a region in which scanning light emission isinitiated is placed outside of a discharging region. A dischargingelectrode to initiate scanning light emission is placed outside of thedischarging region.

When a region in which the scanning light emission is initiated ismatched with a displaying region without redundancy, due to a specialcharacteristic of a head portion of light for scanning, a characteristicof the light emitted in this region is different from that in otherregions.

As shown in FIG. 31, by using a scanning light emitting region beinglarger than a displaying region, light emitted for discharging in a headportion of light for scanning is not used for displaying and only aregion of light emitting for scanning providing a uniform and stablestate can be used and therefore stabilization of displaying and highimage quality can be obtained. Such a configuration can be achieved byplacing a scanning and discharging electrode outside of a displayingregion.

Thirty-Ninth Embodiment

A method for driving a discharging-type backlight employed in athirty-ninth embodiment in which an electrode at least one end of whichis covered by a dielectric is placed on a first and second glasssubstrate 201, gas is fed into a space being provided between the firstglass substrate 101, a portion surrounding the space is sealed,discharging occurs in the space between the first glass substrate 101 byapplication of a voltage and light is emitted by exciting a fluorescentmaterial being arranged between the substrates, includes a step ofconstructing at least one electrode to have the above discharging occurby using a plurality of belt-shaped electrodes, of applying a DC (directcurrent) voltage to one electrode out of the belt-shaped electrodesduring light emission for scanning and-discharging in a region in whichthe belt-shaped electrode emits light for discharging and of applying asine waveform voltage or a rectangular waveform voltage to otherelectrode. FIG. 32 is a diagram explaining wires for electrodes of athirty-ninth embodiment of the present invention. As shown in FIG. 32, ascanning bias voltage is fed to a scanning electrode group 301 beingconnected to a scanning bias voltage switch 303 being in an ON state anda common signal (alternating voltage) is input to a common electrodegroup 302.

By changing a potential in an electrode to which a DC voltage is appliedcorresponding to an intermediate potential of an alternating voltage tobe applied to other electrode, an amplitude of the alternating voltageat each polarity to be applied to the electrode to which the DC voltagehas been applied can be varied.

Discharging occurs by application of an alternating voltage of severalMHz or less between electrodes at least one end of which is covered by adielectric. The discharging occurs when the alternating voltage exceedsa threshold voltage and has a dielectric bear electrical charges so asto generate a voltage having a reverse polarity between electrodes andis terminated.

A subsequent alternating voltage applied from an outside is superimposedon a voltage produced by charging with electricity, which causesoccurrence of a subsequent discharging and a voltage having a reversepolarity to be generated between electrodes and the discharging isterminated.

Fortieth Embodiment

In a method for driving a backlight for an LCD which scans a region oflight emitting for discharging, a DC voltage to be applied to abelt-shaped electrode is scanned. FIG. 33 is a diagram illustrating awaveform of a driving voltage employed in the fortieth embodiment of thepresent invention.

Discharging continues in a stable state when a potential in an electrode(for example, scanning electrode) to which a DC voltage is applied is atan intermediate potential of an alternating voltage applied to otherelectrode (for example, common electrode). By applying a DC voltage in amanner that the applied voltage is drifted from the intermediatepotential of the alternating voltage to other electrode, it is madepossible that a threshold voltage is not exceeded even if asuperimposing voltage by charging with electricity is contained.

Thus, a discharging occurring region can be controlled by changing a DCvoltage. By scanning a DC voltage to be applied to a belt-shapedelectrode of the scanning electrode with an amplitude of an alternatingvoltage maintained at a constant level using the above dischargingcontrol mechanism, scanning can be performed on a region of lightemitting for discharging.

Forty-First Embodiment

In a method for driving a backlight for an LCD, intensity of lightemitted for scanning and discharging is varied by changing a DC voltageto be applied to a belt-shaped electrode.

FIG. 34 is a cross-sectional view showing a backlight of a forty-firstembodiment of the present invention. By setting a DC voltage so as to bedrifted from an intermediate potential within a range in whichdischarging occurs, it is possible to change the intensity of lightemitted for scanning and discharging, that is, average luminance oflight fed from the backlight. A DC voltage to be supplied to a scanningelectrode group 301 through a scanning bias voltage switch 303 is madevariable.

Forty-Second Embodiment

In a method for driving a backlight of a forty-second embodiment, awidth of a region of light emitting for scanning is varied by changing anumber of belt-shaped electrodes to which a DC voltage is applied. Bychanging a number of the belt-shaped electrode to which a DC voltage isapplied, it is made possible to change a width of the region of lightemitted for scanning and to change average luminance of light fed fromthe backlight.

Forty-Third Embodiment

In a method for driving a backlight of a forty-third embodiment, bychanging a frequency of an alternating voltage to be applied to oneelectrode, luminance of light fed from the backlight is changed. Sincean alternating voltage is applied only to the one electrode by employingthe method of the forty-third embodiment, a frequency can be changedeasily and independently without an influence on other characteristicsand calibration of luminance of light fed from the backlight can beeasily made.

Forty-Fourth Embodiment

An LCD of a forty-fourth embodiment is provided with a liquid crystaldisplay section and a discharging-type backlight having characteristicsdescribed in above other embodiments and scanning is performed on thebacklight and the liquid crystal display section in a same period.

Forty-Fifth Embodiment

In a method for manufacturing a backlight section employed in aforty-fifth embodiment, a plurality of backlight units is manufacturedcollectively, as shown in FIGS. 36A and 36B, by forming unit portions ofa plurality of backlight units having scanning electrodes 307, a commonelectrode 313, a dielectric layer, and a fluorescent layer 312 making upa discharging-type backlight on either of two substrates an uppersubstrate 314 and a lower substrate 315, by forming a sealing layer in amanner that it surrounds a region in which discharging occurs in thisunit portion and then feeding gas into each unit portions obtained bybonding and cutting the upper substrate 314 and the lower substrate 315or by feeding gas into a substrate obtained by bonding two substratestogether and then by cutting the bonded substrate.

FIG. 36 is a cross-sectional view explaining manufacturing processes ofthe backlight of the forty-fifth embodiment of the present invention.

As shown in FIG. 36A, the scanning electrode 307 is formed on the lowersubstrate 315 and a common electrode 313 is formed on the uppersubstrate 314. As shown in FIG. 368, the fluorescent layer 312 isformed.

As shown in FIG. 36C, a seal member 316 is mounted on the lowersubstrate 315 and a spacer 317 (for example, glass-like spacer) on theupper substrate 314 Thus, a plurality of unit portions of the backlightis prepared. In the example shown in FIGS. 36A to 36F, a plurality ofscanning electrodes 307 and one common electrode 313 are mounted in eachunit portion.

Then, as shown in FIG. 36D, the upper substrate 314 and the lowersubstrate 315 are stuck.

Next, as shown in FIG. 36E, each of the unit portion is cut forseparation.

Then, as shown in FIG. 36F, gas is fed through a gas feeding hole 318 ina hermetic manner. An alternative method is that after the twosubstrates have been stuck and inert gas has been fed therein/cutting ismade in each of unit portions.

Moreover, each of the unit portions is connected to a scanning drivingsystem of the backlight section. Then, positional calibration relativeto a liquid crystal display section 1 is made to achieve arrangement instacked layers.

At this point, connection is established so that the scanning drivingsystem of the backlight section synchronizes with that of the liquidcrystal display section 1. By operating above, by performing one timeassembling process, a plurality of backlight sections can be obtained.This enables an LCD in which scanning by the liquid crystal displaysection is synchronized with scanning by the backlight section to beprovided at low costs.

Example

An example of the present invention will be described below. FIG. 35 isa cross-sectional view schematically illustrating basic configurationsof a gas discharging-type backlight used in the present invention. InFIG. 35, in the backlight of the example of the present invention, acommon electrode 102 made up of a transparent conductive film made byusing an indium oxide or tin oxide as a main ingredient is formed on anentire surface of a displaying region of a first glass substrate 101.The first glass substrate 101 and the common electrode 102 make up afront glass substrate 100.

On a second glass substrate 201 is formed, in order to control a regionof emitted light, short-book shaped scanning electrodes 202 fabricatedby using a metal thin film or metal particles as a main ingredient whichare arranged in parallel in a direction traveling straight to a scanningdirection or a metal fine particle, on which a white dielectric layer203 is formed and finally a fluorescent material layer 204 to emit lightby being excited using ultraviolet rays is formed. The second glasssubstrate 201, the scanning electrode 202, the dielectric layer 203, andthe fluorescent material layer 204 make up a rear substrate 200.

In the example, the fluorescent material layer 204 is made up of athree-waveform light emitting fluorescent material so that visible lightfed from the fluorescent material layer 204 can be suitably applied to acolor filter in a liquid crystal section and light having a white coloris emitted.

The front glass substrate 100 and the rear glass substrate 200 are stuckto each other with a spherical glass spacer sandwiched between the fontglass substrate 10 and the rear glass substrate 200 in a manner that aninterval between the front glass substrate 100 and the rear glasssubstrate 200 making up a discharging space 300 is kept at a constantlength. The discharging space 300 is filled with gas containing an inertgas as a main ingredient by using frit glass in a portion surrounding abacklight in a hermetic manner.

In the above example, the common electrode 102 is formed on an entiresurface being opposite to the discharging space 360 existing on thefirst glass substrate 101.

The common electrode 102 may be formed on a side of the dischargingspace 300 or may be formed in a same direction as arrangement of thescanning electrode 202 or in a direction orthogonal to the scanningelectrode 202 in a short-book, form.

These configurations are possible so long as discharging occurs by avoltage being applied between the common electrode 102 and the scanningelectrode 202 and a discharging current is limited by a dielectric layerbeing placed between electrodes or by a glass substrate before abreakdown of the dielectric layer occurs (this operation being called“dielectric barrier discharging”.

Moreover, it is necessary that electrodes being placed on a side of adisplaying face, irrespective of whether it is the common electrode 102or the scanning electrode 202, are so configured as to fully passvisible light fed from a fluorescent material and therefore theelectrodes existing on a side of the displaying face are made of atransparent conductive material, a metal mesh, or a like.

The scanning electrode 202 or the white dielectric layer 203 isconstructed of materials that can effectively guide light fed from afluorescent material to a side of the displaying face It is desirousthat the white dielectric layer 203 contains fine particles with a highrefractive index such as titanium oxide and the scanning electrode 202is constructed of materials with a high rate of reflection for visiblelight such as silver, aluminum, or a like.

In a case where the scanning electrode 202 on a side of the rearsubstrate 200 is formed on an entire surface of a displaying region in aplane form, instead of the white dielectric layer 203, a transparentdielectric layer may be used.

Moreover, the scanning electrode 202, if being of a short-book shape,may be so configured that no dielectric layer is mounted on a metalelectrode or that a transparent dielectric layer is formed or that awhite dielectric layer is formed in a region where no metal portionbetween electrodes is formed.

The fluorescent material layer 204 may be formed not only on the rearsubstrate 200 but also on the front substrate 100 on the displayingface.

Also, the fluorescent material layer 204 may be constructed of not avisible light emitting fluorescent layer but an ultraviolet ray emittingfluorescent material or may be so configured that ultraviolet rays beinggenerated by discharge in a gas are taken out as light fed from thebacklight and are used for scanning.

Next, an example of a method for manufacturing the discharging-typebacklight is described below.

The common electrode 102 is fabricated by forming a transparentconductive film containing indium oxide as a main ingredient on a frontsurface of the first glass substrate 101 and by performing patterning onthe resulting transparent conductive film by etching technique using aphotoresist.

The (patterned) common electrode 102 has an electrode portion sectionoutside of the displaying region.

The common electrode 102 is placed in a manner that it is not exposed inthe discharging space 300 at least in the displaying region and isfabricated by forming a dielectric paste containing a material with alow melting point as a main ingredient by using a screen printing methodand by coating a baked transparent dielectric layer with the dielectricpaste.

On the other hand, on the second glass substrate 201 is formed thescanning electrode 202 fabricated by performing patterning on aconductive paste containing Ag (silver) particles as a main ingredientby using the screen printing method and by coating the second glasssubstrate 201 with the obtained conductive paste and by baking thecoated substrate.

The scanning electrode 202 also has an electrode portion section outsideof the displaying region.

The scanning electrode 202 is placed in such a manner that it is exposedin the discharging space 300 at least in the displaying region and isfabricated by being coated with the white dielectric layer 203 obtainedby forming a dielectric paste containing glass with a low melting pointmade of white pigment fine particles using the screen printing methodand by baking the obtained dielectric paste.

On the white dielectric layer 203 is formed a three-waveform lightemitting fluorescent material by a screen printing method which is thenbaked and is used as the fluorescent material layer 204.

Then, a frit glass paste is formed by being discharged in a closed lineform by a dispenser in a portion surrounding an outside of thedisplaying region of the first glass substrate 101 and the second glasssubstrate 201 and the formed frit glass paste is pre-baked.

On the rear glass substrate 201 are formed a hole for introducing gasand an exhaust tube made up of a glass tube.

A backlight panel is fabricated by placing glass balls for a spacer eachhaving a diameter of 0.1 mm to 2 mm between the first glass substrate101 and the second glass substrate 201 and by performing positioning onthe glass balls, by baking and bonding them together.

In order to prevent movement of the glass spacer obtained by a sealingprocess, it is desirous that a concave and convex portion having alength of several to several tens μm in a portion in which the abovetransparent dielectric layer or the white dielectric layer 203 comesinto contact with the glass spacer.

Gas in the above stuck backlight is exhausted through an exhaust tubeuntil a vacuum is produced and, at the same time, the backlight panel isheated so as to promptly exhaust the atmospheric gas being left in thebacklight panel.

After sufficient heating and exhausting, a temperature in the backlightpanel is lowered and Xe (xenon) gas is fed into the discharging space300 in the backlight panel at a pressure of 600 hPa in a hermetic mannerand then the exhausting tube is closed.

As a discharging gas, besides the Xe (Xenon) gas, a pure gas of Ar(Argon), Kr (krypton), or N (nitrogen), or a mixed gas of inert gasesincluding He (Helium) or Ne (Neon) with these gases can be used. Gascomposition and a thickness of the dielectric material layer can becalibrated in such a manner that luminance of emitted light and drivingvoltage are optimized.

Next, a method of scanning and driving by the discharging-type backlightemployed in the embodiment is described,

As shown in FIG. 33, a voltage having a sine wave or a rectangular waveof several kHz to several tens MHz is applied to the common electrode102.

Also, as shown in FIG. 33, to the scanning electrode 202 which does notemit light for discharging is applied a voltage being drifted from anintermediate voltage of an alternating voltage being applied to thecommon electrode 102.

To the scanning electrode 202 that emits light for discharging isapplied a voltage being approximately an intermediate voltage of analternating voltage being applied to the common electrode 102.

In a region where a voltage of the scanning electrode 202, a surface ona side of the discharging space 300 of the dielectric material layerexisting between the common electrode 102 and the scanning electrode 202is charged with electricity and discharging is terminated once. However,reverse-polarity discharging occurs by a voltage, being appliedimmediately, having a reverse polarity in the common electrode 102 andthe discharging is maintained by repetition of these operations.

On the other hand, when a voltage of the scanning electrode 202 isdrifted largely from an intermediate voltage of the common electrode102, if discharging occurs by a large potential difference and isterminated by charging with electricity once, a potential difference issmall at a subsequent voltage having a reverse polarity and continuousdischarging can be avoided.

Moreover, by a voltage being applied to the scanning electrode 202,luminance of emitted light can be changed.

By having a voltage to be applied to the scanning electrode 202 bescanned for every single scanning line or every two or more scanningline blocks, light can be emitted while a scanning line to emit light isbeing selected.

Modulation of a voltage to be fed to the scanning electrode 202 can beperformed at a high speed by a switch fabricated by using, for example,an FET (Field Effect Transistor).

Next, configurations and driving methods for more improvingcharacteristics of scanning light emission in the backlight for scanningof the present invention are described.

When such the scanning discharging as described above is performed, in aregion where the scanning discharging is initiated without occurrence ofdischarging in a surrounding area, discharging is unstable.

As shown in FIG. 28, an auxiliary discharging region being adjacent to aregion in which scanning light emission starts and in which dischargingis maintained continuously or immediately before initiation of scanninglight emission, is formed outside of the displaying region by theauxiliary discharging electrode 104.

These electrodes can be fabricated by using same processes as used forfabricating the common electrode 102 or the scanning electrode 202. Bythe auxiliary discharging, an ion, electron or excited atoms ormolecules can be supplied to a region in which scanning light emissionis initiated and a state of initiation of the scanning discharging canbe stabilized.

Moreover, in the auxiliary discharging electrode 104, it is preferablethat the discharging light emission is inhibited by making small an areaof the auxiliary discharging electrode 104 and by making large athickness of its dielectric material layer in a range in whichdischarging is stable. To prevent light for auxiliary discharging fromleaking into the displaying region, a light intercepting section 105 isformed on a side of the displaying face in the auxiliary dischargingregion (see FIG. 28).

Also, in order to prevent light for the auxiliary discharging from beingconverted to visible light, as shown in FIG. 29, no placement of thefluorescent material in a region in which auxiliary dischargingelectrodes 104 are arranged is an effective idea.

Furthermore, as shown in FIG. 30, formation of the (auxiliarydischarging intercepting) partition wall 106 used to separate theauxiliary discharging region from the scanning discharging region withina range in which an effect by the auxiliary discharging is reduced morethan necessary is also effective in preventing light for the auxiliarydischarging from being converted to visible light.

A voltage being applied to the auxiliary discharging region may be sameas in the scanning discharging region and another driving circuit may beprovided.

In the case of using the other driving circuit, although costs requiredfor using the driving circuit has risen, intensity of auxiliarydischarging can be independently controlled and both a displayingfunction and a driving function can be easily optimized.

Next, in order to more improve characteristics of backlight scanninglight emission, as shown in FIG. 31, a scanning electrode 202 of thedischarging-type backlight is placed outside the displaying region ofthe liquid crystal displaying section 1 and by synchronizing scanningtiming for the liquid crystal displaying section 1 with scanning timingfor the backlight, scanning is performed approximately at a same speed.

In the discharging-type backlight, in some cases, light emission at adischarging end is different in uniformity from the light emission at acentral portion or is dispersed in uniformity. By providing redundancyto a scanning light emission region of the backlight, high reliabilitycan be given to a displaying characteristic of the liquid crystaldisplay panel performing a scanning driving using the backlight, thatis, the scanning-type backlight.

It is clear that characteristics of light emission and scanning drivingbecome better by using the auxiliary discharging in combination.

Next, another example of the discharging-type backlight that can emitlight providing three primary colors (R, G, and B) is described.

In the example, at least one of either the common electrode or thescanning electrode corresponds to a region in which any one of colorsout of the three primary colors ROB appears.

For example, the scanning electrode is formed on the rear substrate in ashort-book form and a strip-shaped partition wall having a height of 100μm to several millimeters is formed in a manner that a region includingthe (short-book shaped) electrode is partitioned. On an inside wall faceof this partition wall is formed a white dielectric layer and arestacked RGB color changing fluorescent material layers in order.

After the white dielectric material layer has been formed in a mannerthat it covers an entire discharging displaying region of the short-bookshaped scanning electrode, the strip-shaped partition wall and the RGBcolor changing fluorescent material layers may be formed. A RGB colorscanning-type backlight is fabricated by manufacturing the frontsubstrate having the common electrode in the way described above and bybonding the front substrate to the rear substrate.

A rectangular waveform voltage or sine waveform voltage having severalkHz to several tens MHz are applied to the common electrode and avoltage is applied to the scanning electrode in a manner that lightemission occurs in a region for each of RGB colors and scanning isperformed.

A state in which the RGB color light emission region is discontinuouscan be controlled by an expanding plate and scanning can be performedindividually on the uniform RGB color light emission region. Byoperating as above, a liquid crystal panel having a high aperture rateand a high light using rate can be obtained without using a colorfilter. Since the high light using rate can be obtained, it is possibleto improve luminance of emitted light and to reduce power consumption.

In the above example, the discharging-type backlight operated by usingdischarge in a gas is explained, however, as the backlight, for example,a field-emission-type backlight in which electrons are accelerated in avacuum and the accelerated electrons is injected into a fluorescentmaterial or an organic electroluminescence-type backlight operated byusing electro-luminescent light may be employed.

It is apparent that the present invention is not limited to the aboveembodiments but may be changed and modified without departing from thescope and spirit of the invention.

What is claimed is:
 1. A system, comprising: a group of scanningelectrodes disposed on a first glass substrate of a backlight, whereinthe group of scanning electrodes are configured to receive a directcurrent voltage; and a group of common electrodes disposed on a secondglass substrate of the backlight, wherein the group of common electrodesare configured to generate a light emitting discharge responsive toapplication of an alternating current voltage.
 2. The system of claim 1,wherein the alternating current voltage comprises at least one of a sinewaveform voltage or a rectangular waveform voltage.
 3. The system ofclaim 1, wherein the group of scanning electrodes and the group ofcommon electrodes are further configured to cause the light emittingdischarge in a gas between the first glass substrate and the secondglass substrate in response to the alternating current voltage exceedinga threshold voltage.
 4. The system of claim 1, wherein the group ofscanning electrodes and the groups of common electrodes are furtherconfigured to vary an intensity of light produced by the light emittingdischarge in response to a variation of the direct current voltage. 5.The system of claim 1, wherein the group of scanning electrodes and thegroup of common electrodes are further configured to vary a luminance oflight produced by the light-emitting discharge in response to avariation of a frequency of the alternating current voltage.
 6. Thesystem of claim 1, further comprising a transparent dielectric layerdisposed on the first glass substrate.
 7. The system of claim 1, furthercomprising a white dielectric layer disposed on the second glasssubstrate.
 8. The system of claim 1, wherein the group of scanningelectrodes comprise belt-shaped electrodes.
 9. The system of claim 1,further comprising an auxiliary discharging electrode configured tocontinuously discharge during scanning of the group of scanningelectrodes.
 10. The system of claim 9, wherein a first area of dischargeassociated with the auxiliary discharging electrode is smaller than asecond area of discharge associated with a scanning electrode of thegroup of scanning electrodes.
 11. The system of claim 9, furthercomprising a fluorescent material disposed on a first region of thesecond glass substrate corresponding to the group of scanningelectrodes, wherein a second region of the second glass substratecorresponding to the auxiliary discharging electrode is free offluorescent material.
 12. The system of claim 9, further comprising apartition wall disposed between a first light emitting regioncorresponding to the auxiliary discharging electrode and a second lightemitting region corresponding to the group of scanning electrodes.
 13. Amethod, comprising: applying a direct current voltage to a group ofscanning electrodes disposed on a first glass substrate of a backlight;and applying an alternating current voltage to a group of commonelectrodes disposed on a second glass substrate of the backlight. 14.The method of claim 13, wherein the applying the alternating currentvoltage comprises applying a sine waveform voltage or a rectangularwaveform voltage.
 15. The method of claim 13, wherein the applying thedirect current voltage and the applying the alternating current voltagefacilitate a discharge in a gas between the first glass substrate andthe second glass substrate.
 16. The method of claim 15, furthercomprising varying an intensity of light emitted by the discharge inresponse to varying the direct current voltage.
 17. The method of claim15, further comprising varying a luminance of light emitted by thedischarge in response to varying a frequency of the alternating currentvoltage.
 18. The method of claim 13, wherein the applying the directcurrent voltage comprises applying the direct current voltage to a groupof belt-shaped scanning electrodes.
 19. A system, comprising means forgenerating a light emitting discharge responsive to an alternatingcurrent voltage applied to a group of common electrodes disposed on afirst glass substrate of a backlight; and means for controlling thelight emitting discharge responsive to a direct current voltage appliedto a group of scanning electrodes disposed on a second glass substrateof the backlight.
 20. The system of claim 19, wherein the means forcontrolling comprises means for varying an intensity of light producedby the light emitting discharge responsive to a variation of the directcurrent voltage.